Coefficient of Conservatism:
Coefficient of Wetness:
R. W. Smith
This is another of the small, weedy prostrate species, native south and west of Michigan, but spreading as a weed into disturbed areas and plantings. First collected by C. Reidy in plantings in East Lansing (Ingham Co.) and by R. W. Smith in Lenawee Co. in 2011.
This species is similar to Euphorbia geyeri in being totally glabrous and with entire leaves, but in addition to the stipule features in the key, it has proportionately much wider leaves, these almost as wide as long, broader than any of our other mat-forming Euphorbia species. In E. geyeri, the leaves are mostly 1.3–2.5 (–3) times as long as wide. When well developed, E. serpens also usually roots at the nodes, while E. geyeri does not.